The principal objective of this proposal is to provide access to a Laser Capture Microdissection system to investigators in the Program in Epithelial Biology. The Program in Epithelial Biology at Stanford provides a research forum for investigators with a common interest in mechanisms and diseases involving epithelial tissues. While each of the investigators uses sensitive techniques to determine gene expression differences within identified cell populations, a rate-limiting step in analysis is the ability to rapidly isolate and analyze pure populations of cells from tissue. Laser Capture Microdissection is a technique developed in 1996 that enables investigators to acquire individual groups of cells from tissue sections, fixed cell cultures and cytotogical preparations. The PixCell lle Microdissection Instrument from Arcturus Inc is currently the best system to perform the technique. The addition of a Laser Capture Microdissection system will significantly extend the research capabilities of the investigators in this program. The specific protocols presented in this proposal address fundamental mechanisms in epithelial growth and morphogenesis that will further our understanding of disease processes involved in athlerosclerosis, non-melanoma skin cancer, tumor metastasis, and axonal regeneration.